Every couple of years, I have to use Sodium Chlorate to kill off stuff
growing in between the bricks on my driveway and then jet wash it followed
by laying down kiln sand to fill in the gaps.

I recently had a gardener in who said that there is something I can buy that
will allow me to protect the bricks and stop stuff growing in between. He
doesn't know what it is called though but said you get it in tubs and it was
expensive.

Anyone know what it is called and where to get it from cheaply?

Thanx

AMO